Device for locating the exact center of the condyle by using extra oral radiography



March 7, 1967 H. F. CHAIKEN DEVICE FOR LOCATING THE EXACT CENTER OF THE CONDYLE BY USING EXTRA ORAL RADIOGRAPHY Filed Nov. 4, 1963 f/VVENTOR. Hyman 1 Uncuken.

FICI5 United States Patent 3,307,262 DEVICE FOR LOCATING THE EXACT CENTER OF THE CONDYLE BY USING EXTRAORAL RADIOGRAPHY Hyman F. Chaiken, Wilkes-Barre, Pa., asslgnor to The J. Bird Moyer Company, Inc., Philadelphia, Pa., a corporation of Pennsylvania Filed Nov. 4, 1963, Ser. No. 321,234 2 Claims. (Cl. 32-19) This invention is directed to a device to be used in conjunction with any X-ray machine, particularly as related to dentistry in the construction of dentures.

An object of this invention is to provide a device to visually establish the exact center of an anatomical member such as a condyle extra orally.

A further and more specific object of the invention is to provide a device to correctly and visually pin-point the exact center of the articulating surface of the head of the condyle which is the upper part of the lower jaw called the mandible.

A further and still more specific object is to provide a device facilitating the fabrication of a perfectly balanced denture which will give the patient more comfort and also eliminate troublesome and painful areas especially in the lower jaw.

In following the method taught in textbooks and at present used for establishing correct occlusion in the fabrication of dentures, the center of the condyle is arbitrarily located on the side of the face at approximately ten to thirteen millimeters from the tragus of the ear. The tragus is a cartilagenous projection before the opening of the ear.

The mandible or lower jaw is classed as a hinge-axis joint which has its own center of rotation and must not be compromised. When the occlusion on dentures is off only one millimeter the bite is definitely out of harmony with the temporo-mandibular articulation.

This error and miscalculation may result not only in faulty and uncomfortable dentures, but may cause other very serious complications. To carry out a procedure of correct mechanics in denture fabrication it is necessary that the exact center of the starting point be visually and correctly established and an arbitrary location not be assumed.

The invention will be best understood from a consideration of the following detailed description taken with the accompanying drawings forming a part of the specification, it being understood however, that slight changes and modifications may be made in the structure of the present invention so long as such changes or modifications do not depart from the invention as expressed in the appended claims.

In the drawings:

FIGURE 1 is a front view in perspective of the present device of the invention for use in locating the center of an anatomical member in the head of an individual.

FIGURE 2 is a front elevational view of the device of the present invention when positioned on the patients head.

FIGURE 3 is a view similar to FIGURE 2 except that the device includes the X-ray film.

FIGURE 4 is a side view of the patient showing the condyle exposed and with an arm of a face bow positioned adjacent the condyles center.

3,307,262 Patented Mar. 7, 1967 FIGURE 5 is a view of the exposed X-ray film showing the desired coincidence between the center of the condyle and the external position of a metallic dot forming an element of the device of the invention.

Referring now more particularly to the drawings, 1 indicates the head bow which is made of a flexible metal so it can be adjusted to the patients cranium. Reference characters 2 and 3 designate spoonshaped pads made of silicone rubber wrapped around the metal, which are used to stabilize the head bow in position. The long narrow shaft is a continuation of the head bow.

The element designated 4 is one of the most important elements of the device constituting the present invention. This element consists of a clear strip of plastic in which two metal dots 7 are imbedded one on each side. The purpose for the two dots is that this indicator will be used on the right and the left side of the face. The two metal dots include one for the right and one for the left side of the face.

Index 4 also has attached to it superimposed metal bar 5. The metal bar is attached to the index in the center part only. This allows a free space between the bar and the plastic strip on each side for the placement and retention of the X-ray film 8, as shown in FIGURE 3.

Index 4 also is attached to spring metal clip 6. Spring metal clip 6 is adapted to grip the extended long narrow shaft of the head bow 1, and is slidably adjustable thereon to facilitate the movement of index 4 up or down said long narrow shaft of head bow 1 as required to adjust the position of metal dot 7 in preparing to locate the center of the condyle.

In order to locate the center of an object an arbitrary point on the side face of the patient in front of the tragus 12 is selected.

The index 4 embodying the metal dots 7 is so positioned on face bow 1 in place on patients head that the metal dot is placed on the selected point. The X-ray film is inserted between the index 4 and one free end of the metai bar 5. Since the index is made of clear plastic, it will not show on the X-ray film after the film is developed. Only the metal dot will be detected on the film of the condyle.

If the X-ray taken as above described shows that the dot 7 is not in the center of the condyle 9, the device is replaced and a closer point is selected and X-rayed again until the exact center is established by coincidence between the center and the metal dot 7 on the X-ray film, as shown at 10 on FIGURE 5. Since this type of X-ray requires only one third of a second for exposure, there is little or no danger from too much radiation.

I claim:

1. Device for locating externally the center of an interior anatomical member such as a condyle, said device comprising: (A) a flexible head bow adapted to fit over and grip the head of a patient and having at least one continuation sufiiciently long to extend across the external surface overlaying said interior anatomical member of said patient; (B) a transparent indicating member adjustably fastened to said continuation and having at least one small metal mass embedded therein near an extremity thereof; and (C) film-holding means fastened to said indicating member and adapted to removably hold X-ray film over said metal mass.

2. Device for locating externally the center of an interior anatomical member such as a condyle, said device 3 4 comprising: (A) a flexible head bow adapted to fit over adapted to removably hold X-ray film over each of said and grip the head of a patient and having at least one metal masses.

continuation sufiiciently long to extend beyond the skin surface covering said interior anatomical member of said References Cited y the Examine! patient; (B) positioning means gripping said continuation 5 UNITED STATES PATENTS and adapted to slidable adjustment thereon; (C) a transparent indicating member fastened to said positioning means and having a small metal mass embedded therein near each of its extremities; and (D) film-holding means RICHARD GAUDET Prlmary Examiner fastened at its center to said indicating member and 10 ROBERT MORGAN, Examine!- 1,497,259 6/1924 Bonoff 3220' 

1. DEVICE FOR LOCATING EXTERNALLY THE CENTER OF AN INTERIOR ANATOMICAL MEMBER SUCH AS A CONDYLE, SAID DEVICE COMPRISING: (A) A FLEXIBLE HEAD BOW ADAPTED TO FIT OVER AND GRIP THE HEAD OF A PATIENT AND HAVING AT LEAST ONE CONTINUATION SUFFICIENTLY LONG TO EXTEND ACROSS THE EXTERNAL SURFACE OVERLAYING SAID INTERIOR ANATOMICAL MEMBER OF SAID PATIENT; (B) A TRANSPARENT INDICATING MEMBER ADJUSTABLY FASTENED TO SAID CONTINUATION AND HAVING AT LEAST ONE SMALL METAL MASS EMBEDDED THEREIN NEAR AN EXTREMITY THEREOF; AND (C) FILM-HOLDING MEANS FASTENED TO SAID INDICATING MEMBER AND ADAPTED TO REMOVABLY HOLD X-RAY FILM OVER SAID METAL MASS. 